Smoking cigarettes has been known to be a major cause of diseases such as a lung cancer, bronchitis, and coronary or peripheral artery disease. Individual chemical substances contained in cigarettes have already been recognized as a carcinogen, and passive smoking has been elucidated to have carcinogenicity recently, so that smokeless chewing tobacco and snuff are also listed in carcinogenic substance list in the United States. Among the components contained in cigarettes, nicotine, which is a colorless volatile liquid alkaloid, has high toxicity of irritating and paralyzing the nerve tissue such as cerebral nerve, cerebellum and spinal cord while having calming effect, excitement effect and pleasure-giving effect. Therefore, there have been continuously reported that nicotine relating to the incidences of lung cancer, pharyngeal cancer, esophageal cancer and gastric cancer.
Nicotine also has mental dependence, so that a continual intake of nicotine by smoking or the like may cause nicotine dependence. For example, when a heavy smoker quits smoking, withdrawal symptoms are seen in a short time period and craving for smoking increases. If the smoker cannot tolerate his craving for smoking, and takes more nicotine to avoid the symptoms and torment, his health is staked at a higher risk.
In those times, campaigns for nonsmoking and moderation in smoking have been run worldwide, and a smoking population tends to be decreased every year. There is a trend toward restriction in smoking in public facilities and public transportation, so that a smoker frequently faces a situation in which he is forced to stop smoking. However, mental and physical torments may be caused by breaking a smoking habit in many cases, and a sudden drop in an intake of nicotine may cause serious withdrawal symptoms. For this reason, there is an earnest need for a method showing an effect on prohibiting or moderating smoking gradually without causing any problems.
As such methods, a food or a medicament such as nicotine gum, and candy, drop or gum, containing various plant extracts, an inorganic substance and the like has been so far known (Japanese Patent Laid-Open No. Sho 4-46119, Japanese Patent Laid-Open No. Sho 61-63243, Japanese Patent Laid-Open No. Sho 62-296840, Japanese Patent Laid-Open No. Sho 62-296840, Japanese Patent Laid-Open No. Hei 8-308544, Japanese Patent Laid-Open No. Sho 82-42582, Japanese Patent Laid-Open No. Hei 7-18076, and Japanese Patent Laid-Open No. Sho 48-85722). Moreover, a method of causing discomfort by inhaling a certain chemical substance simultaneously with cigarette smoke using a pipe or the like, and a method of promoting anti-smoking by absorbing nicotine into body using a nicotine pad or nicotine nasal spray have been used. The principles for prohibiting or moderating smoking by these means are classified into three categories: (1) suppression for craving for smoking by paralyzing gustation and the like; (2) promotion of a detoxification/excretion of nicotine in the body; and (3) supply of nicotine by a cigarette substitute. However, in a case where nicotine is absorbed transdermally or the like, nicotine exists internally after all, so that this method cannot be said to be good for health. Further, even when a reduction in the craving for smoking is achieved, there would be a risk for dependence on the cigarette substitute used. The above-mentioned food or the like has a little effect, and would not satisfactorily gratify smokers' gustation who is generally accustomed to nicotine, so that withdrawal symptoms originated from prohibition or moderation of smoking could not be fundamentally suppressed. Accordingly, it is often the case that a smoker cannot help smoking, so that their effectiveness has a certain limit.